Power supply circuit



Jun 23,1936- L. w. WICKERSHEIM 2,045,428

POWER SUPPLY CIRCUIT Filed May 1, 1955 Armeugz Patented June 23, 1936 I UNITED STATES PATENT OFFICE POWER SUPPLY CIRCUIT Lyle W. Wickersheim, Essex Fells, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application May 1, 1935, Serial No. 19,149 8 Claims. (Cl. 171312) This invention relates to power supply circuits supplying constant voltage to a load circuit in case and more particularly to power circuits for sup- 'of failure of the space discharge device. plying constant potential to space discharge de- In the power supply circuit employed to illusvices. trate the invention a potentiometer is connected One object of the invention is to provide a in parallel to a gas-filled space discharge device 5 power circuit that shall have a potentiometer and in series with a fixed resistance to a variable shunted across a gas-filled space discharge devoltage supply circuit which may be a telegraph vice for supplying power to load circuits and that battery. The potentiometer may supply potential shall have improved means for controlling the to any suitable circuits such, for example, as the 0 operation of the space discharge device. grid circuits of vacuum tubes employed in tele- 10 Another object of the invention is to provide graph circuits. The gas-filled space discharge dea power circuit comprising a potentiometer shuntvice which is connected in parallel to the potened by a space discharge device and connected in tiometer preferably has threecold electrodes and series with a fixed resistance to a variable voltage is filled with gas preferably in the helium group.

source for supplying constant potential to vac- Two of the electrodes in the gas-filled device are 15 uum tubes that shall have improved means for employed for triggering ofi purposes to start a triggering on the space discharge device and for discharge. The third electrode in combination controlling the potentiometer in case of failure with one of the other electrodes serves to provide of the device. a discharge path having a constant voltage after A further object of the invention is to provide a break-down of the device. 20 a power supply circuit for vacuum tubes that shall A single figure in the accompanying drawing have a gas-filled space discharge device connected is a diag am tic V of a Power eireuit I to a variable voltage source in series with a fixed structed in accordance with the invention.

resistance and in parallel to a potentiometer, that e r g to the drawing a potentiemetel is shall temporarily raise the voltage impressed on Shown c ec in pa a c c to gas-filled 25 the device to break it down and that shall insert Space d s r device 2 and in Series with a main resistance in series with said potentiometer in e s a ce 3 to a m' d d Variable Veltage Source case of failure of the device. 4. The main resistance which is connected in It is well known that a mercury vapor or a gasseries with the variable voltage source 4 absorbs filled space discharge device has a constant povariations in voltage of the source so that con- 30 I tential drop across its discharge path when in stant potential is impressed across the potentiomoperation. The current flow through the device eter- The gas-filled pa discharge device 2 has will vary according to the potential impressed on a C ns t Potential p 0 t irrespective of the electrodes of the device, but the voltage drop the Voltage p ess 0 it the v t p across the discharge path in the device will rethrough it will be h me. However, the cur- 35 main constant. This characteristic of mercury nt flow through the device v i s n a c r an vapor or gas-filled space discharge devices may with the Potential of t Source The main be utilized for supplying constant potential to a sistfenee has a Potentlal drop according to the load circuit If a g fi] 1ed space discharge variations of current flow through the gas-filled vice is connected in parallel to a potentiometer j discharge device so that agconstant Voltage 40 and in series with a fixed resistance to a variable e across the potfmtmmeter' In the voltage source a constant potential will be imshupt t of the potentiometer aroupd the pressed across the potentiometer. The potentidevlce 2 are tncluded' i control relstance 6 and an ad ustable resistance 1. The adJustable ometer may be employed as a source of constant resistance 1 included in the potentiometer circuit 45 potennal for space t g devlces' around the gas-filled device 2 serves to adjust the In meFcury devlce the Same as m potential maintained across the potentiometer filled device having cold electrodes the striking and to adjust the voltage impressed on the elec Voltage necessary to start discharge is much trodes of the space discharge device 2. The relay higher than the voltage u red to su a 5 is provided with an armature a for controlling to charge after it has been started. Inthe present an al r 9 nd n tur In for controlling inventi n m ns r pr v f r triggering ff a protective resistance H. A relay 1: having two a gas-filled tube by a voltage raised only a small armatures l3 and I4 is connected in circuit with amount above the sustaining voltage. Moreover, the gas-filled space discharge device 2. The aremergency means are provided for approximately mature I3 of the relay l2 serves to short-circuit 55 the control resistance 6 when the relay is in operative position. The armature Id of the relay I2 serves to complete a circuit for operating an alarm I5 when the relay is in released position.

The gas-filled space discharge device 2 is provided with three cold electrodes I6, II, and I8. The electrodes I6 and II are located relatively close together and serve to trigger oil" the device. The electrode I 8 is disposed further away from the electrode I'I than the electrode I6 and serves to form a discharge path after triggering ofr" between the electrodes I6 and II. The sustained voltage between the electrodes II and I8 is steady Whereas the sustained voltage between the electrodes I6 and I] would not be substantially con. stant. A resistance I9 is provided between the electrodes I6 and I8 to permit discharge or triggering oiT between the electrodes I6 and Ill and to insure a majority of current passing between the electrodes II and I8 after breakdown of the device. a

In the drawing the potentiometer I is illustrated as the source of potential for the grids of vacuum tubes 20. It is, of course, apparent that the potentiometer I may be employed as a source of potential for other types of load circuits. It is also apparent that the load circuits may be directly connected across the gas-filled space discharge device 2 if so desired. voltmeter H is provided for indicating the voltage drop across the potentiometer I.

Assuming the relays 5 and I2 are in released position and potential is supplied to the circuit from the battery 4, the control resistance 6 will be in circuit with the potentiometer I and will in sure sufiicient voltage being impressed across the electrodes I6 and I! of the device 2 to trigger off the device. The voltage impressed across the electrodes I6 and I! in'one form of the device may be of the order of 15 to 95 volts. Upon breakdown of the device 2 a discharge path is formed between the electrodes I! and I8. A potential of the order of 208 volts would be necessary to break the device between the electrodes II and I8. The relay I2 is operated for short-circuiting the control resistance 6 so as to reduce the voltage impressed on the space discharge device 2. The short circuiting of the control resistance 6 also insures correct voltage being impressed across the potentiometer I. At this time the relay 5 is operated for short-circuiting the protective resistance It so that the discharge device 2 may operate to maintain substantially constant voltage drop across the potentiometer I. The protective resistance II connected between the second and third electrodes of the gas-filled device 2 serves to permit triggering oiT of the gas-filled device and after a breakdown of the device permits a majority of the current to discharge across the first and third electrodes. The relay I 2, as before set forth is assumed to have a negligible resistance value.

In case of failure of the space discharge device 2, the relay I2 would be released. The armature I 1 would complete a'circuit for operating the alarm I5 in case of failure of the device 2. At the same time an armature I3 would remove the short circuit around the control resistance 6 so as to approximately maintain normal voltage drop across the potentiometer I. In case of failure of the circuit through the potentiometer the relay 5 will be released to complete a circuit for operating an alarm 9.-

Modifications in the circuit and in the arrangement and location of parts may be made within the spirit and scope of the invention and such modifications are intended to be covered by the appended claims.

What is claimed is:

1. In combination, a variable source of potential, a main resistance, a gas-filled space discharge device having cold electrodes connected to said source in series with said main resistance, a potentiometer connected in shunt circuit to said device, and means comprising a relay connected in circuit withsaid device for increasing the potential across the device to break it down and for reducing the potential impressed on the device after breakdown has occurred to maintain constant voltage across said potentiometer.

2. In combination, a variable source of potential, a main resistance, a gas-filled space discharge device connected to said source in series with said main resistance, said device having three cold electrodes, a potentiometer connected in shunt circuit to said device, and means for increasing the potential across two electrodes of said device to trigger off the device and efiect a conducting path including the third electrode and one of the first electrodes and for reducing the potential impressed on the device when the device has broken down to maintain constant voltage across said potentiometer.

3. In combination, a variable source of potential, a main resistance, a gas-filled space discharge device connected to said source in series with said main resistance, said device having three cold electrodes, a potentiometer connected in shunt circuit to said device, and means for triggering ofi" said device by a path including two electrodes located relatively close together, for effecting a path including the third electrode and one of the first electrodes when the tube is broken down to maintain constant voltage across said potentiometer, and for inserting resistance in series with said potentiometer in case of failure of said device to eifect substantially normal voltage drop across the potentiometer.

4. In combination, a variable source of potential, a main resistance, .a gas-filled space dis charge device having three cold' electrodes and connected to said source in series with said main resistance, a control resistance and a potentiometer connected to said source in series with the main resistance and in parallel circuit to said device, and means comprising a relay connected in series with said device for governing said control resistance to triggerofl said device by a path including two of said electrodes, said relay when in operative position completing a short circuit around said control resistance.

5. In combination, a variable source of potential, a main resistance, a gas-filled space discharge device connected to said source in series with said main resistance, a potentiometer connected in parallel circuit to said tube and in series with said main resistance and said source, a control resistance and means comprising a relay having the operating coil thereof in series with said device for effectively connecting said control resistance in series with said potentiometer to trigger ofi said device upon starting and to maintain substantially normal voltage across said 320- tentiometer in case of failure of said device and for efiectively short-circuiting said control resistance upon operation of said device.

6. In combination, a variable source of potengas-filled space dissaid source in series said device having tial, a main resistance, a charge device connected to With said main resistance,

three cold electrodes, a potentiometer and a control resistance connected in parallel circuit to said'device and in series with main resistance and the source, a relay having the energizing coil thereof connected in series with a protective resistance and said device for governing said control resistance, a relay having-the operating coil thereof connected in circuit with said potentiometer for controlling said protective resistance, and a permanent resistance connecting two electrodes of said device.

'7. In combination, a variable source of potential, a main resistance, a control resistance, a protective resistance, a potentiometer, a gasfilled space discharge device connected to said with said main resistance,'said device having three cold electrodes, a relay for governing said control resistance, the operating coil of -said relay being connected in series with said protective resistance and said device, said relay in released position effectively connecting said control resistance in series with the potentiometer to impress a said device and operating upon breakdown of the device to short-circuit the control resistance, and a second relay connected potentiometer for short-circuiting said protective resistance to insure constant potential across the potentiometer.

8. In combination, a grounded variable source of potential, a main resistance, a potentiometer, a relay, a protective resistance, a gas-filled space discharge device having three cold electrodes, one of said electrodes being connected in series with said main resistance to said source, a second electrode of said device located relatively close to said first electrode to form a triggering off path and connected to the third electrode by a resistance and the third electrode being connected in series with said protective resistance and the coil of said relay to ground, and a second relay connected in series with said potentiometer and a control resistance between ground and the first electrode, said first mentioned relay in released position insuring sumcient, potential being impressed upon the first two mentioned electrodes to trigger all said device and in operative position serving to short-circu't said control resistance and said second relay serving to short-circuit said protective resistance when potential is impressed across said potentiometer.

LYL WICKERSHEIM. 

